python: Fix kprobe quota test breakage, add uprobes

As part of the funccount work, the kprobe quota test doesn't fail
early when adding multiple kprobes at once (with `event_re`), but
rather only when the 1000th probe is being added. Revert to the old
behavior, which fixes the `test_probe_quota` test. Add similar test
for uprobes, `test_uprobe_quota`, which tests the recently-added
uprobe regex support.

src/python/bcc/__init__.py

@@ -409,7 +409,9 @@ class BPF(object):
 
         # allow the caller to glob multiple functions together
         if event_re:
-            for line in BPF.get_kprobe_functions(event_re):
+            matches = BPF.get_kprobe_functions(event_re)
+            self._check_probe_quota(len(matches))
+            for line in matches:
                 try:
                     self.attach_kprobe(event=line, fn_name=fn_name, pid=pid,
                             cpu=cpu, group_fd=group_fd)
@@ -672,7 +674,9 @@ class BPF(object):
         name = str(name)
 
         if sym_re:
-            for sym_addr in BPF.get_user_adddresses(name, sym_re):
+            addresses = BPF.get_user_addresses(name, sym_re)
+            self._check_probe_quota(len(addresses))
+            for sym_addr in addresses:
                 self.attach_uprobe(name=name, addr=sym_addr,
                                    fn_name=fn_name, pid=pid, cpu=cpu,
                                    group_fd=group_fd)

tests/python/test_probe_count.py

@@ -67,6 +67,10 @@ class TestProbeQuota(TestCase):
         with self.assertRaises(Exception):
             self.b.attach_kprobe(event_re=".*", fn_name="count")
 
+    def test_uprobe_quota(self):
+        with self.assertRaises(Exception):
+            self.b.attach_uprobe(name="c", sym_re=".*", fn_name="count")
+
     def tearDown(self):
         self.b.cleanup()